Question

At what rate per cent per annum will ₹640 amount to ₹774.40 in 2 years, interest being compounded annually? ​

Answer 1

Answer:

answer is below

Step-by-step explanation:

We know, A=P(1+100r​)n

               ∴774.40=640(1+100r​)2

               640774.40​=(1+100r​)2

               6400077440​=(1+100r​)2

               100121​=(1+100r​)2

               (1011​)2=(1+100r​)2

               1011​=1+100r​

               100r​=1011​−1

               100r​=1011−10​

               100r​=101​

                   r=10100​=10

Rate r=10% per annum.